Eleven children who were legally blind at birth can now see — thanks to a one-time gene therapy developed by MeiraGTx. The children were born with Leber congenital amaurosis type 4 (LCA4), a rare genetic disorder caused by mutations in the AIPL1 (aryl-hydrocarbon-interacting protein-like 1) gene, which leaves affected children with only enough vision to distinguish light from darkness.

Building on this groundbreaking success, MeiraGTx has licensed the therapy, known as AAV-AIPL1, to Eli Lilly in a deal valued at up to $475 million, including $75 million upfront and additional milestone payments. The agreement grants Lilly exclusive global rights to the treatment for LCA4, while also providing access to MeiraGTx’s broader ophthalmology gene therapy technologies, including proprietary capsid and promoter libraries that enhance precision delivery, and partial rights to the company’s Riboswitch platform, which allows for adjustable gene expression.

For Lilly, the deal represents more than a single therapy — it is a strategic entry into the rapidly advancing field of ophthalmic gene therapy, following its recent acquisition of Adverum Biotechnologies and its late-stage therapy for wet age-related macular degeneration (wAMD). At a time when many large pharma companies have pulled back from gene therapy amid high costs and manufacturing challenges, Lilly’s twin investments in Adverum and MeiraGTx position it among a small group of players doubling down on the space.

The results behind the deal

In early clinical studies in the UK, four children initially received a single subretinal injection of AAV-AIPL1 and showed measurable improvements in visual acuity, as published in The Lancet. The program later expanded to 11 children, all of whom gained functional vision, with measurable improvements in retinal structure and visual cortex activity. Families also reported profound changes in communication, behavior, and social integration, underscoring the therapy’s broader impact on daily life.

Safety data were also encouraging. Aside from one case of cystoid macular edema in a treated eye, no significant adverse effects were reported. These results, combined with the therapy’s orphan drug and rare pediatric disease designations in both the US and Europe, set the stage for accelerated regulatory review. MeiraGTx plans to file for marketing authorization approval in the UK and a biologics license application with the FDA in 2025.

“We are excited to partner with MeiraGTx to bring transformative treatments to patients around the world suffering from eye diseases, starting with AAV-AIPL1, which has shown the unprecedented ability to restore vision in children who were born legally blind,” said Andrew Adams, Lilly Group Vice President, in the press release.

In essence, Lilly is acquiring a platform that has demonstrated both scientific innovation and real-world efficacy, providing a potential blueprint for future ophthalmology gene therapies. For a pharmaceutical giant looking to expand into this emerging field, AAV-AIPL1 offers both a high-impact patient outcome and a strategic foothold in a space poised for growth.

A stronghold in ophthalmology gene therapies

Less than a month before the deal to license AAV-AIPL1, Lilly announced plans to acquire Adverum Biotechnologies, whose lead candidate, ixo-vec, is a one-time gene therapy in late-stage development for wAMD. Unlike traditional treatments, which require frequent anti-VEGF (vascular endothelial growth factor) injections to block the VEGF protein from causing abnormal blood vessel growth in the retina, Ixo-vec is designed to turn the retina into a “biofactory” that continuously produces aflibercept, a protein that inhibits the growth of leaky blood vessels in the eye. Early clinical results show sustained efficacy and a favorable safety profile, with most patients remaining free from supplemental aflibercept injections for over a year.

While AAV-AIPL1 targets a rare pediatric disorder, ixo-vec addresses a highly prevalent global condition affecting more than 20 million people worldwide. Importantly, Lilly’s acquisition of Adverum also brings access to its proprietary AAV.7m8 vector platform and in-house manufacturing expertise.

Combined with the MeiraGTx deal, which gives Lilly access to platform technologies such as optimized vectors, promoters, and the Riboswitch system, the company now has the platforms and production capacity to develop and deliver multiple next-generation gene therapies in the future.